1. Field of the Invention
The present invention relates to a pendulum box, and more particularly to a pendulum box for a clock.
2. Description of the Related Art
A conventional pendulum box for a clock in accordance with the prior art shown in FIGS. 3 and 4 comprises a tumbler seat 1 having a lower end provided with a receiving case 2 to receive an electromagnetic coil (not shown) and a circuit board (not shown), a pendulum mover 3 having an upper end pivotally mounted on an upper end of the tumbler seat 1 and a lower end provided with a fixing seat 31 for fixing a magnet 311 and formed with a snap hole 33, a pendulum rod 32 pivotally mounted on the pendulum mover 3 and having an upper end snapped into the snap hole 33 of the pendulum mover 3, and a cover 11 mounted on the tumbler seat 1 to cover the pendulum mover 3. The tumbler seat 1 is used to rotate hour, minute and second hands (not shown) of the clock. The fixing seat 31 of the pendulum mover 3 is located adjacent to the receiving case 2 of the tumbler seat 1. Thus, when the magnetic field of the electromagnetic coil in the receiving case 2 of the tumbler seat 1 is changed, a force is produced between the magnet 311 of the pendulum mover 3 and the electromagnetic coil of the tumbler seat 1 so as to push the pendulum mover 3 to oscillate so as to move the pendulum rod 32.
However, the upper end of the pendulum mover 3 is pivotally mounted on the upper end of the tumbler seat 1, and the pivot connection of the pendulum mover 3 and the tumbler seat 1 is not located at the balance point of the pendulum mover 3, so that the pendulum mover 3 is oscillated too rapid, thereby decreasing stability of oscillation of the pendulum mover 3 and the pendulum rod 32. In addition, the upper end of the pendulum rod 32 is snapped into the snap hole 33 of the pendulum mover 3, so that the pendulum rod 32 is not combined with the pendulum mover 3 rigidly and stably. Thus, the pendulum rod 32 is easily vibrated or detached from the pendulum mover 3 during movement.
Another conventional pendulum box for a clock in accordance with the prior art shown in FIGS. 5–7 comprises a tumbler seat 41 having a lower end provided with a receiving case 42 to receive an electromagnetic coil (not shown) and a circuit board (not shown), a pendulum mover 43 having an upper end pivotally mounted on an upper end of the tumbler seat 41 and formed with a protruding stud 431 and a lower end provided with a fixing seat 44 for fixing a magnet (not shown) and formed with a snap hole 433, an upper pendulum rod 45 having a lower end secured on the protruding stud 431 of the pendulum mover 43, a lower pendulum rod 432 pivotally mounted on the pendulum mover 43 and having an upper end snapped into the snap hole 433 of the pendulum mover 43, and a cover 46 mounted on the tumbler seat 41 to cover the pendulum mover 43. The upper pendulum rod 45 provides a balance effect, so that the lower pendulum rod 432 is oscillated smoothly and stably.
However, the upper end of the lower pendulum rod 432 is snapped into the snap hole 433 of the pendulum mover 43, so that the lower pendulum rod 432 is not combined with the pendulum mover 43 rigidly and stably. Thus, the lower pendulum rod 432 is easily vibrated or detached from the pendulum mover 43 during movement.